Build the Farming room on the right side of the Bunker (where the Forges and Cement Mixers are). Room size should be 5 blocks wide, 6 blocks long and 3 blocks high. Only 1 row of flooring will be installed, rest will be opened and ready for Farm Plots.

We need to build a Farming Room Shaft, basically a 1 block width chimney going all the way to the surface. This will allow sunlight to reach the crops underground. To make sure it’s in the middle, place wood frames on the ground as illustrated and step on the center wood frame. Look straight up and start digging upwards until you reach the surface. Place wood frames under you as you’re moving upwards.

On the surface, dig around the hole and place 8 Wood Frames and upgrade them to Concrete. Install 1 Metal Bars to prevent zombies or animals falling inside. Use the Advanced option to make sure the bars are flush with the surface of the blocks.

Replace all stone walls with Wood Frame Blocks and upgrade.

Replace stone ceiling with Wood Frame Blocks and upgrade.

Place 25 Farm Plots in the empty spots on the ground and plant seeds. In 3 days time you’ll have beautiful full grown plants.